Conventional memory elements that include two terminals include two conductive layers, and a variable resistance portion provided between the two conductive layers. The memory elements are capable of reversibly changing the resistance of the variable resistance portion by applying proper voltage stress between the two conductive layers, and can operate as memory.
The conventional memory elements requires, however, the variable resistance portion to perform writing and erasing of data, which change the resistance between the two terminals, storage of memory in the ON state or OFF state, a rectifying function in the forward direction and the reverse direction of the bias voltage, and control of the voltage and the current in each operating state.